Final answer:
The network topology in which each node connects to exactly two other nodes is known as a ring topology.
Step-by-step explanation:
A network topology where each node connects to exactly two other nodes is known as a ring topology. This is characterized by its circular arrangement where each node connects to two others on either side, and the last node is connected to the first, forming a ring. In contrast, a full mesh topology would have each node connected to every other node, a partial mesh topology has some nodes connected to multiple others but not all, and a star topology has all nodes connected to a central hub.